1. Field of the Invention
The present invention relates to orthopaedic instruments, and, more particularly, to an apparatus and method of attaching an orthopaedic reamer to an orthopaedic driver.
2. Description of the Related Art
Orthopaedic reamers and drivers may be used to prepare the acetabulum for hip joint prosthesis. A rotary tool provides the motive force and is connected to the driver which is connected to the reamer. The drivers generally have a shaft and a reamer end. Reamers are generally hemispherical in shape and attach to the reamer end at the base of the hemisphere. The interior portion of the reamer is known as the debris cavity.
Connecting the driver reamer end to the reamer is known to include attachment of the driver to the base of the reamer. The reamer base can include various backing plates, crossbars and pins which the driver grips. In manufacturing such a reamer, the hemispherical shell can be deep drawn and then assembly of the reamer base to the backing plate, etc. is required. Therefore, this type of design requires multiple production steps including labor and cost intensive methods such as welding, grinding and polishing. Another disadvantage of known mounting methods includes the cost and time to manufacture the various backing plates, etc.
In use, the designs discussed above are problematic in that backing plates and the like mounted to the reamer base block the debris cavity. Such mounting techniques also have surfaces which do not have line of sight access, being blocked by either the hemispherical shell or a surface of the backing plate, thereby making the reamer difficult to clean and sterilize. Given the fact that these instruments are required to be sterile before use and are used in a sterile field (the operating room), every precaution must be exercised in cleaning the instruments, which makes a difficult cleaning procedure time intensive.
When the reamer is used to prepare the acetabulum for hip joint prosthesis, variation in the size of the acetabulum for the human population requires a range of sizes of acetabular reamers, a specific size of the acetabular reamer being determined by the hip joint size of the person undergoing hip joint prosthesis. The different sizes of acetabular reamers are generally specified by different radii of curvature, or diameters, of the hemispherical shell. Some of the known methods of mounting reamers to drivers, because of the attachment of the base of the reamer to the driver, and therefore a dependency on the reamer diameter, require modifications to the driver or different drivers for different size reamers. This increases the cost of a tool set that can accommodate a wide range of hip joint size.
What is needed in the art is apparatus and method of attaching a reamer to a driver that provides ease of manufacturing the reamer, minimizes or eliminates the debris cavity blockage, is suitable for easy and thorough cleaning and sterilization and in which a single driver can be used for a range of reamer sizes.